Cinematographic objective



Feb. `l4, 1933. l, KITROSER 1,897,262

CINEMATOGRAPHIC OBJECT IVE Filed Oct. l5, 1930 NVENTOR @9g/0 o n m BY M1 M" ATTORNEY Patented Feb. 14, 19.33

vUNITED STATESl PATENT OFFICE ISAAC KITROSER, OF PARIS, FRANCE, ASSIGNOR TO KELLER-DORIAN CORPORATION, NEW YORK, N. Y., A CORPORATION OF DELAWARE CINEMATOGRAPHIC OBJECTIVE Application'aied october 1s, lso. seriamo. 488,305.

The present invention has for its object the transforming of the ordinary photographic objective into an objective with a very wide angle. -The present invention places before the ordinary objective an additional lens which provides a wide angle foil the lens. The quality of the new objective can be used to advantage with all kinds of films but it is Avery advantageous for taking 10. pictures with a. goferedfilm for cinematography. The principle of collimation requires the employment of a collimatric lens near the film. It is advantageous in such constructions although the color filter is placed at the focus of the collimatric lens, to provide an objective which will give a very long focus for the collimatric lens. In the present imrovement, I have invented a system which iias a very wide angle field for the objective and a very long focus for the collimatrlc lens.

While my invention is capable of embodiment in many different forms, by way of illustration I'have shown only one embodiment of my invention in the accompanying drawing,

' 25 in which The figure is a` transverse section of an objective made in accordance with my invention.

In the drawing, I have shown a goifered film 1, having in front thereof a collimatric lens 2, in front of which "I place an objective comprising a mounting 3 containing an ordinary photographic objective comprising as the posterior lenses a coconcavo-convex lens 4, a bi-convex lens 5, a. color filter 6, comprising two glass plates having between them a color layer comprising three parallel bands of eq'ual area which are respectively blue, green and red; and containing as the anterior lenses, a concavo-concave lens 7 and a biconvex lens 8. It is to be understood that many other types of ordinary objectives can be used for this purpose. In front of the said ordinary objective, furthermore, I place a negative lens system which I place in the anterior focal plane or in front of the anterior focal plane of the said ordinary objective. This'is comprised of a bi-concave lens 9 and a concavo-convex lens 10.. In constructing the complete objective, where f is the focus of the negativeobjective 9, 10 and f1, the focus of the ordinary objective 4, 5, 7, 8 and the distance between the principal planes of the ordinary objective and the negative objective is E,- the total focus of the new objective comprisin the ordinary objective and the nega-4 tlveo jective is f i F f 1fl fE When E=f1, that is when the negative lens isv placed in the focal plane of the ordinary objective,

If, however, E f1 and f o, or less than o, then F f1 because the factor E -I- f x f 1f-WE 85 or that E+ f f fr'i'E 1 Therefore, w f1, because of the fact that Eff f1 I With these mathematical formulae, a. lens can be constructed and the new objective as desired can be determined.

For example, I can transform an ordinarycinematographic objective of f1=35. mm. and f/2 opening into a new objective made in accordance with 100 my invention by placin in front of the said objective, a negative o jective having a focus of l f= 100 mm. 6 with the distance between the principal planes E=51.67 mm.

The new combined objective now has a to- 10 tal focus j F= mm. and the collimatric lens of this objective -will have accordingly a new focus In the above example, the ne ative ob'ective would, for example, be as ollows: he radius of curvature of the near face 141, R1,

zo R1=' -77.9 mm.,

, the radius of curvature of the surface 12, R2, R,= +36 mm.,

and the radius ofcurvature of the surface as 13, R.,

Rs 89.1 mm.

The thickness of the center of the lens 9, e1, would be so e1=2 mm.,

and the central thickness of the lens 10, e2, e2=7 .1 mm.

8. This distance may, for example, be in-l creased by 4 mm., and the coma will then have disappeared.

It is to be understood, however, that many changes can be made in this construction, and that, for example,'the negative objective can be made of a different number and arrange# ment of the lenses than those shown in the drawing.

While I have described my invention above in detail, it is to be understood that many changes may be made therein without departing from the spirit of my invention.

I claim: 1. A photographic objective, comprising a collimatric lens, an ordinary objective adapted for use therewith and a ne ative lens located in the neighborhood o the anterior focal Aplane of the ordinary objective. 2. v photographic objective, comprising a collimatric lens, an ordinary objective adapted for use there-with and a ne ative lens Iocated in front of -the anterior ocal plane of the ordinary objective.

3. A photographic objective, comprising a collimatric lens, an ordinary objective ada ted for use therewith and a ne ative lensll cated in the neighborhood o the anterior focal plane of the ordinary objective adapted to produce a wider angle for the eld and a lon er focus for the collimatric lens than wit merely the ordinary objective.

4. A photographic objective, comprising a collimatric lens,.an ordinary objective ada ted for use therewith and a ne ative lens lbf` cated in front of the anterior ocal plane of the ordinary objective adapted to produce a Vwider angle for the field and a longer focus 7. Incombination, a goffered film, a color filter and a photographic objective, com-Y prising a. collimatric lens, an ordinary objective adapted for use therewith and a negative lens located in the neighborhood of the anterior focal plane of the ordinary objective adapted to produce a wider angle for the field and alonger focus for the collimatric lens than with merely theordinarv objective.

8. In combination, a goffered lilm, a color filter and a photo raphic objective, comprising a collimatric ens, an ordinary objective adapted for use therewith and a negative lens located in front of the anterior focal plane of the ordinary objective ada ted to roduce a wider angle for the fiel and a lbn er focus for the collimatric lens than wit merely the ordinary objective.

9. A photographic objective correctedfor coma, comprising a collimatric lens, an ordinary objective adapted for use therewith and a negative lens located in the neighborhood of the anterior focalv plane of the ordinary objective.

10. A photographic objective corrected for coma, comprislng a colllmatric lens, an ordinary objective adapted for use therewith and a negative lens located in front of the anterior focal plane of the ordinary objective.

11. A photographic objective corrected for coma, comprising a collimatric lens, an ordinary objective adapted for use therewith and a negative lens located in the nei hborhood of the anterior focal plane of t e or dinary objective adapted to produce a widery anule for the eld and a longer focus for the colIimatric lens than with merely the ordinary objective.

12`. A photographic objective corrected for coma, comprising a collimatric lens, an ordinary objective adapted for use therewith and a. negative lens located in front of the anterior focal plane of the ordinary objective adapted to produce a wider angle for the field and a longer focus for the collimatric lens than with merely the ordinary objective.

13. In combination, a goffered film, a color filter and a. photographic objective, corrected for coma, comprising a collimatric lens, an ordinary objective adapted for use therewith and a negative lens located in the neighborhood of the anterior focal plane of the` ordinary obj ective.

14. In combination, a gofi'ered film, a color filter and a photographic objective corrected for coma, comprising a collimatric lens, an ordinary objective adapted for use therewith and anegative lens located in front of the anterior focal plane of the ordinary objective.

15. In combination, a goffered film, a color filter and a photographic objective corrected for coma, comprising a collimatric lens, an ordinary objective adapted for use therewith and a negative lens located in the neighborhood of the anterior focal plane of the ordinary objective adapted to produce a wider angle for the field and a longer focus for the collimatric lens than with merely the ordinary objective.

16. In combination, a goffered film, a c0101 filter and a. photographic objective corrected for coma, comprising a collimatric lens, an ordinary objective adapted for use therewith and a negative lens located `in front of the anterior focal plane of the ordinary objective adapted to produce a wider angle for the field and a longer focus for the collimatric lens than with merely the ordinary objective. 17. A photographic objective corrected for coma, comprising a collimatric lens` an ordi- 4 nary objective adapted for use therewith and a negative lens located in front of the-anterior focal plane of the ordinary objective, the correction for coma being made by locating the posterior lenses of the ordinary objective farther away from the anterior lenses thereof.

19. A photographic objective corrected for coma, comprisinor a collimatric lens, an ordinary objective adzapted for use therewith and a negative lens located in the neighborhood of the anterior focal plane of the ordinary objective adapted to produce a wider angle for the field and a longer focus for the collimatric lens than with merely the ordinary objective, the correction for coma being made by locating the posterior lenses'of the ordinary objective farther away from the anterior lenses thereof.

20. A photographic objective corrected for coma, comprising a collimatric lens, an ordinary objective adapted for use therewith and a negative lens located in front of the anterior focal plane of the ordinary objective adapted to produce a wider angle for the field ma e by locating the posterior lenses of the ordinary objective farther away from the anterior lenses thereof.

22. In combination, a goffered film, a color filter and a photographic objective corrected for coma, comprising a collimatric lens, an ordinary objective adapted for use therewith and a negative lens located in front of the anterior focal plane of the ordinary objective,

the correction for coma being made by locating the posterior lenses of the ordinary objective farther away from the anterior lenses thereof.

23. In combination, a goffered film, a color filter and a photographic objective corrected for coma, comprising a collimatric lens, an ordinary objective adapted for use therewith and a negative lens located in the neighborhood of the anterior focal plane of the ordinary objective adapted to produce a wider angle for the field and a longer focus for the collimatric lens than with merely the ordinary objective, the correction for coma being made by locating the posterior lenses of the ordinary objective farther away from the anterior lenses thereof.

24. In combination, a gofiered film, a color filter and a photographic objective corrected for coma, comprising a collimatric lens, an ordinary objective adapted for use therewith and a negative lens located in front of the anterior focal plane of the ordinary objective adapted to produce a wider angle for the field and a longer focus for the collimatric lens than with merely the ordinary objective, the V,

correction for coma being made by locating the posterior lenses of the ordinary objective 4 mames rther away from the anterior lenses there-l 25. A photo aphic objective, comprising a collimated o jective containing at least 5 three lenses, a color filter having a plurality of different colored zones, adapted for use therewith, and a negative lens 'located in the neighborhood of the anterior focal plane of ,the objective. Y 26. A photographic objective, comprising a collimated objective containing at vleast three lenses, a color ilter having a plurality of different colored zones, adapted for use therewith, and a negative lens located in the neighborhood of the anterior focal plane of the objective, the color filter being located Within,v the objective.

' ISAAC KITROSER. 

